Rudder size and sweep

[wsnowdon]

Can I say that I found Stuart Badgers article excellent and very
thorough. After many years of building scale models, I cheat and
icrease rudder area by about 10 - 15 percent to get blade area into
the water flow along the hull. I like his analogy to an aircraft
wing. The majority of modelers use their rudders like an air brake,
slamming full rudder on in a fraction of a second, visibly slowing
the model down, and thereby slowing the water flow over the rudder
and the subsequent loss of flow over the rudder reduces its effect by
a large amount. (you watch next time you are at the water- Sailors
trying to push the stick out of the transmitter and the model
hesitating! Remember, you can scale models and propulsion but you
cannot scale water density- your model is sailing in treacle compared
to its full size counterpart. EASE the rudder on and you will have
more instant control rather that yanking your waterbrake out! May
your wakes always be twins. Walter Snowdon.